== I want to start this new application. What do you advise? == <!--T:2-->

+

+

<!--T:3-->

We all agree that there are plenty of KDE applications that need to be written. But there are also a lot of existing kde applications that need your help.

We all agree that there are plenty of KDE applications that need to be written. But there are also a lot of existing kde applications that need your help.

−

To see the areas where help is needed, check this page.

+

<!--T:4-->

+

To see the areas where help is needed, check [http://www.kde.org/jobs/ this page].

−

Before starting a new application, it's always a good idea to check [http://www.kde-apps.org/ KDE-Apps.org] for existing applications and to ask on the kde-devel@kde.org mailing-list whether someone is already working on a similar project.

+

<!--T:5-->

+

Before starting a new application, it's always a good idea to check [http://www.kde-apps.org/ KDE-Apps.org] and other open source software hosting services like [https://github.com/ GitHub], [https://code.google.com Google Code], and [http://sourceforge.net/ SourceForge] for existing applications and to ask on the [https://mail.kde.org/mailman/listinfo/kde-devel kde-devel] mailing-list whether someone is already working on a similar project.

−

====I am a developer, how can I contribute to KDE?====

+

== I am a developer, how can I contribute to KDE software? == <!--T:6-->

−

Check the open jobs from the job list, there is certainly one that you can take. KOffice and KDevelop, despite being very praised, have very few developers, so you might check there. There is no need to be a KDE core-developer to help. KDE is very modular so you can perfectely improve one area without knowing how the whole system works.

+

−

You can also ask on kde-devel if someone needs help on an application.

+

<!--T:7-->

−

Use the latest version of KDE and spot things that are needed. A theme generator? A konsole schema editor? Improve a game? There is always a small feature missing. Go and implement it!

+

Calligra and KDevelop, despite being very praised, have very few developers, so you might check there. There is no need to be a developer of the KDE workspaces or KDE platform libraries to help. The whole range of KDE software is very modular so you can perfectly improve one area without knowing how others work.

−

Are you familiar or attracted with a specific field? See if there is a related application that could use your help. Or write one. KDE needs more non-geek oriented applications.

+

<!--T:8-->

+

You can also ask on [https://mail.kde.org/mailman/listinfo/kde-devel kde-devel] if someone needs help on an application.

+

Use the latest version of your favourite KDE software and spot things that are needed. A theme generator? A konsole schema editor? Improve a game? There is always a small feature missing. Go and implement it!

−

====I am not a developer, how can I help?====

+

<!--T:9-->

+

Are you familiar or attracted with a specific field? See if there is a related application that could use your help. Or write one. KDE especially welcomes more non-geek oriented applications.

+

+

== I am not a developer, how can I help? == <!--T:10-->

+

+

<!--T:11-->

There are plenty of tasks that don't require development skills. Write reviews of applications for the promoting of KDE (see the [https://mail.kde.org/mailman/listinfo/kde-promo kde-promo] mailing-list), help the documentation team (see [http://l10n.kde.org/docs/ i18n.kde.org/doc]), help the translations (see [http://l10n.kde.org/ i18n.kde.org]), help to filter the incoming bugs (see [https://bugs.kde.org/ bugs.kde.org]).

There are plenty of tasks that don't require development skills. Write reviews of applications for the promoting of KDE (see the [https://mail.kde.org/mailman/listinfo/kde-promo kde-promo] mailing-list), help the documentation team (see [http://l10n.kde.org/docs/ i18n.kde.org/doc]), help the translations (see [http://l10n.kde.org/ i18n.kde.org]), help to filter the incoming bugs (see [https://bugs.kde.org/ bugs.kde.org]).

−

====Where can I find images of Konqi the dragon?====

+

== Where can I find images of Konqi the dragon? == <!--T:12-->

+

+

<!--T:13-->

The Konqi for some people SDK is at [ftp://ftp.kde.org/pub/kde/devel/konqi_sdk.tar.bz2 ftp.kde.org/pub/kde/devel/konqi_sdk.tar.bz2]<br />

The Konqi for some people SDK is at [ftp://ftp.kde.org/pub/kde/devel/konqi_sdk.tar.bz2 ftp.kde.org/pub/kde/devel/konqi_sdk.tar.bz2]<br />

It was posted to artist.kde.org before that site ceased to be updated.

It was posted to artist.kde.org before that site ceased to be updated.

−

Further images are on [http://kde.org/stuff/clipart.php KDE merchandise].

+

<!--T:14-->

+

Further images are on [http://kde.org/stuff/clipart.php KDE merchandise]. Also you can find some unofficial Konqi images and models from [http://forum.kde.org/viewforum.php?f=254 Create Konqi with Krita Contest] and [http://sourceforge.net/projects/supertuxkart/ SuperTuxKart] game.

−

====What is the level required to contribute to KDE? What should I learn? What should I read?====

+

== What is the level required to contribute to KDE? What should I learn? What should I read? == <!--T:15-->

−

You need to know C++. Read the Qt tutorials and browse the Qt docs to get familiar with what's available with Qt. Then read the KDE tutorials and browse architecture and documentation. You can also read the KDE Book, it can not harm. But you don't have to be familiar with the whole KDE architecture to become a kde developer. Using kde's technologies is quite easy, so concentrate on what you really need, you can learn the other bits later on.

You need to know C++. Read the [http://qt-project.org/doc/qt-4.8/tutorials.html Qt tutorials] and browse the Qt docs to get familiar with what's available with Qt. Then read the [http://techbase.kde.org/Development/Tutorials KDE tutorials] and browse architecture and documentation. You can also read the [http://flossmanuals.net/kde-guide/ KDE Book], it can not harm. But you don't have to be familiar with the whole KDE architecture to become a KDE developer. Using KDE's technologies is quite easy, so concentrate on what you really need, you can learn the other bits later on.

Then, browse the source, look for the examples directories, see how the other did code their applications. Reading and writing code is the best way to learn.

Then, browse the source, look for the examples directories, see how the other did code their applications. Reading and writing code is the best way to learn.

−

====What is SVN? How do I get KDE from SVN?====

+

== How do I get KDE software from the KDE git or SVN repositories? == <!--T:17-->

−

See the [[Getting_Started/Sources/Anonymous SVN|Anonymous SVN page]].

+

+

<!--T:18-->

+

See the [[Special:myLanguage/Getting_Started#Building_and_Running_KDE_Software_From_Source|Building and Running KDE Software From Source]] section on the [[Special:myLanguage/Getting_Started|Getting Started]] page.

* Your app must compile with the latest version of KDE (git master or SVN trunk).

−

* your app must be stable.

+

* Your app must be stable.

−

* your app must be maintained. You will probably get a good deal of bug reports and wishes. People expect you to fix the bugs and implement the wishes that make sense.

+

* Your app must be maintained. You will probably get a good deal of bug reports and wishes. People expect you to fix the bugs and implement the wishes that make sense.

See also the next question.

See also the next question.

−

====Is it better to develop inside or outside KDE?====

+

== Is it better to develop inside or outside KDE? == <!--T:27-->

+

+

<!--T:28-->

As core developer Waldo Bastian explains in a copyrighted mail:

As core developer Waldo Bastian explains in a copyrighted mail:

−

----

+

<blockquote>

−

:Being part of KDE means that you have to work together with others. Such cooperation brings along advantages but it also brings along responsibilities.

+

Being part of KDE means that you have to work together with others. Such cooperation brings along advantages but it also brings along responsibilities.

−

: <br />

+

<br /><br />

−

:Some of those advantages are: your code ends up on all distro's, people might fix your bugs, you get free translations and documentation, you get tons of bugreports.

+

−

: <br />

+

<!--T:29-->

−

:On the other side there are disadvantages and responsibilities: you will have to communicate with other developers about your work, other people might make changes to your code, you will have to respect release freezes, you get tons of bugreports and people actually expect that you fix them as well (what are they smoking?), people expect you to maintain your code.

+

Some of those advantages are: your code ends up on all distro's, people might fix your bugs, you get free translations and documentation, you get tons of bugreports.

−

: <br />

+

<br /><br />

−

:You can't chose for the advantages and ignore the responsibilities that come with it, it's a complete package, it's both or nothing.

+

−

: <br />

+

<!--T:30-->

−

:In general it should be the author of a piece of software that chooses to put his application in SVN. We usualy don't put software in KDE SVN unless the author wishes to do so. The other way around, if the author prefers to work on his application outside SVN then that's his right as well. Unless there is a split in the actual group of people working on the application it makes no sense to fork the development of an application because of that.

+

On the other side there are disadvantages and responsibilities: you will have to communicate with other developers about your work, other people might make changes to your code, you will have to respect release freezes, you get tons of bugreports and people actually expect that you fix them as well (what are they smoking?), people expect you to maintain your code.

−

: <br />

+

<br /><br />

−

:BUT... by putting your code under and open source license and putting it in KDE SVN you give the world at large, as well as KDE in particular, the irrevocable right to use your code. And KDE will use that right at its discretion to protect the interests of KDE, even if that goes against the wishes of the author at that point in time.

+

−

----

+

<!--T:31-->

+

You can't chose for the advantages and ignore the responsibilities that come with it, it's a complete package, it's both or nothing.

+

<br /><br />

+

+

<!--T:32-->

+

In general it should be the author of a piece of software that chooses to put his application in KDE's repositories. We usually don't put software in KDE's repositories unless the author wishes to do so. The other way around, if the author prefers to work on his application elsewhere then that's his right as well. Unless there is a split in the actual group of people working on the application it makes no sense to fork the development of an application because of that.

+

<br /><br />

+

+

<!--T:33-->

+

'''BUT'''... by putting your code under and open source license and putting it in a KDE repository you give the world at large, as well as KDE in particular, the irrevocable right to use your code. And KDE will use that right at its discretion to protect the interests of KDE, even if that goes against the wishes of the author at that point in time.

+

</blockquote>

+

+

<!--T:34-->

It is important to know that but don't be afraid. Usually, things work very well. In 5 years, it has only happened once that a developer had his work put kept in KDE while he wanted to remove it.

It is important to know that but don't be afraid. Usually, things work very well. In 5 years, it has only happened once that a developer had his work put kept in KDE while he wanted to remove it.

−

====How do I get SVN access to kde?====

+

== How do I get write access to KDE repositories? == <!--T:35-->

−

See full article at [[Contribute/Get_a_SVN_Account|Contribute > Get a SVN Account]].

+

+

<!--T:36-->

+

See full article at [[Special:myLanguage/Contribute/Get_a_Contributor_Account|Get a KDE Contributor Account]].

−

Send a mail to sysadmin (at) kde (dot) org justify why you need SVN access. Make sure to specify your full name and e-mail address, if the From field in your mails doesn't specify them.

+

<!--T:37-->

+

Go to [http://identity.kde.org KDE Identity], fill out the form and describe why you need write access. Make sure to specify your full name and e-mail address.

−

Please include the name of your bugs.kde.org account, if non-existent please create one so that it can be given usual developer rights. Closing bugs.kde.org reports with keywords in commit comments only works if the email address of your SVN and bugs.kde.org accounts match. You can change your bugs.kde.org address in the Bugzilla user settings.

+

<!--T:38-->

+

Please also include the name of your [https://bugs.kde.org/ bugs.kde.org] account, if non-existent please create one so that it can be given usual developer rights. Closing bugs.kde.org reports with keywords in commit comments only works if the email address of your KDE Identity and bugs.kde.org accounts match. You can change your bugs.kde.org address in the Bugzilla user settings.

−

You can currently choose between the standard SVN protocol (https using a password) and the svn+ssh using an ssh key. If you choose https, send also an encrypted password (for instance using useradd dummy ; passwd dummy ; grep dummy /etc/passwd /etc/shadow) and see also the tutorial. If you choose svn+ssh, send a public ssh key instead (e.g. {{path|~/.ssh/id_dsa.pub}})

+

<!--T:39-->

+

Git requires use of an ssh key, and new accounts for SVN must also choose the svn+ssh protocol. Send a public ssh key (e.g. {{path|~/.ssh/id_dsa.pub}})

See also [[#How do I create a SSH key?]]

See also [[#How do I create a SSH key?]]

+

<!--T:40-->

If you are contributing to an application that is not yours, it is a good idea to first submitting your coding as patches to the author and let him apply them. If the author is not maintaining his application, you might become the new maintainer...

If you are contributing to an application that is not yours, it is a good idea to first submitting your coding as patches to the author and let him apply them. If the author is not maintaining his application, you might become the new maintainer...

−

Although there is no restrictions on SVN rights, we expect you not to mess up other developers' code without their consent.

+

<!--T:41-->

−

You must also respect the feature freezes of the release schedule (published on developer.kde.org)

+

Although there are few restrictions on repository commit rights, we expect you not to disrupt other developers' code without their consent. You must also respect the feature freezes of the release schedule (published on [[Schedules]] page)

−

A detailed list of rules you should follow when committing to the KDE SVN repository are listed in the KDE SVN Commit Policy.

+

<!--T:42-->

+

A detailed list of rules you should follow when committing to KDE repositories are listed in the [[Special:myLanguage/Policies/SVN_Commit_Policy|KDE Commit Policy]].

−

====My app is not stable but I would like to have it in KDE====

+

== My app is not stable but I would like to have it in KDE == <!--T:43-->

−

As a first step, we can put it in playground (=kde-alpha). Develop it there and when it is ready, ask your app to be moved to the appropriate KDE package or the extragear module.

+

−

====I don't want to lose my SVN history.====

+

<!--T:44-->

−

This is no longer possible with Subversion. Maybe in the future, if the server is upgraded and allows that.

+

As a first step, we can put it in playground, which is essentially "kde-alpha". Develop it there and when it is ready, request that your app to be moved to the appropriate KDE package or the extragear module.

−

====What is kdebindings?====

+

== I don't want to lose my SVN history. == <!--T:45-->

−

It contains Qt bindings for Ruby, PHP, C# to use Qt classes with those langages, KDE bindings for Ruby, PHP, python to use KDE classes with those langages, and XParts to embed non-KDE apps as a KPart. Check the [[Development/Languages|binding page]] of TechBase.

+

−

====Does the feature freeze apply to playground?====

+

<!--T:46-->

+

This is no longer possible with Subversion. Maybe in the future, if the server is upgraded and allows that. Note that for git this is not an issue.

+

+

== What is kdebindings? == <!--T:47-->

+

+

<!--T:48-->

+

It contains Qt bindings for Ruby, PHP, C# to use Qt classes with those langages, KDE bindings for Ruby, C#, python to use KDE classes with those langages, and XParts to embed non-KDE apps as a KPart. Check the [[Special:myLanguage/Development/Languages|binding page]] of TechBase.

+

+

== Does the feature freeze apply to playground? == <!--T:49-->

+

+

<!--T:50-->

No, playground are not a released packages. The same is true for kdereview and extragear: they are not frozen and released. But if you want your app to move to a package, ask for it before the beta-release.

No, playground are not a released packages. The same is true for kdereview and extragear: they are not frozen and released. But if you want your app to move to a package, ask for it before the beta-release.

−

====Can I have a stable and an unstable KDE on the same computer?====

+

==Can I have a stable and an unstable KDE on the same computer?== <!--T:51-->

−

Yes, check the Building 2 Versions documentation.

+

−

====How do I know which version of Qt/KDE I am using?====

+

<!--T:52-->

+

Yes, check Building KDE Software from git.kde.org video series:

+

* [http://www.youtube.com/watch?v=cqnNVmJocR4 Building KDE Software from git.kde.org Part 1]

+

* [http://www.youtube.com/watch?v=OBJjk5q__Cc Building KDE Software from git.kde.org Part 2]

+

* [http://www.youtube.com/watch?v=SgwEnLeqsg8 Building KDE Software from git.kde.org Part 3]

−

<tt>kde-config</tt> and all kde programs accept <tt>--version</tt> as argument.

+

== How do I know which version of Qt/KDE I am using? == <!--T:53-->

−

====Qt-copy or Qt from qt.nokia.com : if one were doing a clean build of trunk, which would be preferable?====

+

<!--T:54-->

+

<tt>kde-config</tt> and all KDE programs accept <tt>--version</tt> as argument.

+

+

==Qt-copy or Qt from qt.digia.com: if one were doing a clean build of trunk, which would be preferable?== <!--T:55-->

+

+

<!--T:56-->

You can use either. They are binary compatible (forward and backward). There can be, however, a few bugfixes in qt-copy over the most recent Qt release. Especially if building from qt-copy, pay attention to the apply-patches script.

You can use either. They are binary compatible (forward and backward). There can be, however, a few bugfixes in qt-copy over the most recent Qt release. Especially if building from qt-copy, pay attention to the apply-patches script.

−

====How can I checkout a single directory from a SVN module?====

+

== How can I checkout a single directory from a SVN module? == <!--T:57-->

+

+

<!--T:58-->

Checkout the top-level dir with 'svn co -N /modulename', 'cd modulename', 'svn up admin' to get the admin/ dir and then finally checkout the dir you want with 'svn up subdir'

Checkout the top-level dir with 'svn co -N /modulename', 'cd modulename', 'svn up admin' to get the admin/ dir and then finally checkout the dir you want with 'svn up subdir'

+

<!--T:59-->

For instance, to get only reaktivate from playground/utils:

For instance, to get only reaktivate from playground/utils:

−

svn co -N /playground/utils; svn up reaktivate

+

<code>svn co -N /playground/utils; svn up reaktivate</code>

Then compile as usual.

Then compile as usual.

+

<!--T:60-->

The same answer applies to the question "How do I get a single language out of kde-i18n?".

The same answer applies to the question "How do I get a single language out of kde-i18n?".

+

<!--T:61-->

If you don't know the name of the directory you want to check out, you can browse websvn.kde.org to find it.

If you don't know the name of the directory you want to check out, you can browse websvn.kde.org to find it.

−

====How can I get one of the KDE application as a standalone tarball?====

+

== How can I get one of the KDE application as a standalone tarball? == <!--T:62-->

+

+

<!--T:63-->

kdesdk/scripts/svn2dist is a script to extract an application from the KDE source tree and package it as a standalone application.

kdesdk/scripts/svn2dist is a script to extract an application from the KDE source tree and package it as a standalone application.

−

====How do I close my own bug reports?====

+

== How do I close my own bug reports? == <!--T:64-->

−

If you reported a bug that is fixed in a new release of KDE but is still reported as open, you can close it. It might happens because your bug is the same as another one, or simply because the developer fixed something without noticing that it would correct your bug.

+

+

<!--T:65-->

+

If you reported a bug that is fixed in a new release of KDE but is still reported as open, you can close it. It might happen because your bug is the same as another one, or simply because the developer fixed something without noticing that it would correct your bug.

+

+

<!--T:66-->

You can do that from your Subversion commit. To do so, append to your commit message a line like this:

You can do that from your Subversion commit. To do so, append to your commit message a line like this:

−

<tt>BUG: XXXXX</tt><br />

+

<!--T:67-->

−

Where <tt>XXXXX</tt> is the bug report you want to close. If the report you're closing is adding a new feature, you can use FEATURE instead of BUG. <br /><br />

+

<Code>BUG: XXXXX</code> where '''''XXXXX''''' is the bug report you want to close. If the report you're closing is adding a new feature, you can use FEATURE instead of BUG.

−

Managing a bug list is a huge task for the developers and they usually have a lot of bugs listed, some being fixed already without their knowledge, some being unreproducable, some without enough information to be corrected, etc. If you can help managing and updating the list of outstanding bug, you will be gladly welcome. And you will receive an even happier welcome if you provide a patch.

+

+

<!--T:68-->

+

Managing a bug list is a huge task for the developers and they usually have a lot of bugs listed, some being fixed already without their knowledge, some being unreproducible, some without enough information to be corrected, etc. If you can help by managing and updating the list of outstanding bugs, you will be gladly welcome. And you will receive an even happier welcome if you provide a patch.

+

+

== How do I create a SSH key? == <!--T:69-->

−

====How do I create a SSH key?====

+

<!--T:70-->

SSH makes use of two keys: a private key and a public key. You should keep the private key secret at all times and only place it on machines over which you have direct control. Public, shared, and community machines are not suitable environments to store SSH private keys. Take action to help prevent theft of your SSH private key data. Setting a password on your SSH private key will help reduce the risks involved with private key theft.

SSH makes use of two keys: a private key and a public key. You should keep the private key secret at all times and only place it on machines over which you have direct control. Public, shared, and community machines are not suitable environments to store SSH private keys. Take action to help prevent theft of your SSH private key data. Setting a password on your SSH private key will help reduce the risks involved with private key theft.

+

<!--T:71-->

Generate a key pair for each major location you work from. This helps to reduce the impact when your key gets stolen.

Generate a key pair for each major location you work from. This helps to reduce the impact when your key gets stolen.

When someone obtains access to your private key, your key can be abused in attempts to compromise KDE servers. Well known open source projects have been compromised this way in the past, YOU must help us to make sure that this doesn't happen with KDE servers as well. For that reason it is important to notify sysadmin (at) kde (dot) org immediately when you notice that someone may have had access to your private key for example when a computer on which it was stored has been hacked or infected with a virus, worm or trojan.

When someone obtains access to your private key, your key can be abused in attempts to compromise KDE servers. Well known open source projects have been compromised this way in the past, YOU must help us to make sure that this doesn't happen with KDE servers as well. For that reason it is important to notify sysadmin (at) kde (dot) org immediately when you notice that someone may have had access to your private key for example when a computer on which it was stored has been hacked or infected with a virus, worm or trojan.

+

<!--T:72-->

If you choose to make a backup of your SSH private key data, please ensure that any such backup is stored in a secure manner as well.

If you choose to make a backup of your SSH private key data, please ensure that any such backup is stored in a secure manner as well.

+

<!--T:73-->

For the practical part, the following command can be used to generate a SSH private/public key pair with

For the practical part, the following command can be used to generate a SSH private/public key pair with

−

ssh-keygen -t dsa

+

<code>ssh-keygen -t dsa</code>

This will create a private key as {{path|~/.ssh/id_dsa}} and a public key as {{path|~/.ssh/id_dsa.pub}}.

This will create a private key as {{path|~/.ssh/id_dsa}} and a public key as {{path|~/.ssh/id_dsa.pub}}.

−

There are times when you may want to use a key of a different name to the default, perhaps to use seperate keys for different projects. To let SSH know which key you want to use for KDE.org, you can keep a list of servers and their corresponding keys in ~/.ssh/config. For example,

+

<!--T:74-->

−

Host svn.kde.org

+

There are times when you may want to use a key of a different name to the default, perhaps to use separate keys for different projects. To let SSH know which key you want to use for KDE.org, you can keep a list of servers and their corresponding keys in ~/.ssh/config. For example,

−

IdentityFile ~/.ssh/id_dsa_kde

+

{{Input|1= Host svn.kde.org

+

IdentityFile ~/.ssh/id_dsa_kde }}

In order to use SSH to access KDE servers you need to send your public key to sysadmin (at) kde (dot) org.

In order to use SSH to access KDE servers you need to send your public key to sysadmin (at) kde (dot) org.

−

====How can I monitor changes made by others?====

+

== How can I monitor changes made by others? == <!--T:75-->

−

The kde-commits mailinglist carries automatic notifications for all changes made in the KDE SVN repository. The KDE-Commits mailinglist is very high traffic. An alternative is CommitFilter which allows you to get notification for only those areas that interest you.

+

+

<!--T:76-->

+

The [https://mail.kde.org/mailman/listinfo/kde-commits kde-commits] mailinglist carries automatic notifications for all changes made in the KDE repositories. The KDE-Commits mailinglist is very high traffic. An alternative is [http://commitfilter.kde.org/ CommitFilter] which allows you to get notification for only those areas that interest you.

Before starting a new application, it's always a good idea to check KDE-Apps.org and other open source software hosting services like GitHub, Google Code, and SourceForge for existing applications and to ask on the kde-devel mailing-list whether someone is already working on a similar project.

Calligra and KDevelop, despite being very praised, have very few developers, so you might check there. There is no need to be a developer of the KDE workspaces or KDE platform libraries to help. The whole range of KDE software is very modular so you can perfectly improve one area without knowing how others work.

You can also ask on kde-devel if someone needs help on an application.
Use the latest version of your favourite KDE software and spot things that are needed. A theme generator? A konsole schema editor? Improve a game? There is always a small feature missing. Go and implement it!

Are you familiar or attracted with a specific field? See if there is a related application that could use your help. Or write one. KDE especially welcomes more non-geek oriented applications.

There are plenty of tasks that don't require development skills. Write reviews of applications for the promoting of KDE (see the kde-promo mailing-list), help the documentation team (see i18n.kde.org/doc), help the translations (see i18n.kde.org), help to filter the incoming bugs (see bugs.kde.org).

[edit] What is the level required to contribute to KDE? What should I learn? What should I read?

You need to know C++. Read the Qt tutorials and browse the Qt docs to get familiar with what's available with Qt. Then read the KDE tutorials and browse architecture and documentation. You can also read the KDE Book, it can not harm. But you don't have to be familiar with the whole KDE architecture to become a KDE developer. Using KDE's technologies is quite easy, so concentrate on what you really need, you can learn the other bits later on.
KDE TechBase and doc.qt.digia.com (also in your $QTDIR/doc/html) are invaluable resources, take advantage of them.
Then, browse the source, look for the examples directories, see how the other did code their applications. Reading and writing code is the best way to learn.

[edit] How do I get KDE software from the KDE git or SVN repositories?

Being part of KDE means that you have to work together with others. Such cooperation brings along advantages but it also brings along responsibilities.

Some of those advantages are: your code ends up on all distro's, people might fix your bugs, you get free translations and documentation, you get tons of bugreports.

On the other side there are disadvantages and responsibilities: you will have to communicate with other developers about your work, other people might make changes to your code, you will have to respect release freezes, you get tons of bugreports and people actually expect that you fix them as well (what are they smoking?), people expect you to maintain your code.

You can't chose for the advantages and ignore the responsibilities that come with it, it's a complete package, it's both or nothing.

In general it should be the author of a piece of software that chooses to put his application in KDE's repositories. We usually don't put software in KDE's repositories unless the author wishes to do so. The other way around, if the author prefers to work on his application elsewhere then that's his right as well. Unless there is a split in the actual group of people working on the application it makes no sense to fork the development of an application because of that.

BUT... by putting your code under and open source license and putting it in a KDE repository you give the world at large, as well as KDE in particular, the irrevocable right to use your code. And KDE will use that right at its discretion to protect the interests of KDE, even if that goes against the wishes of the author at that point in time.

It is important to know that but don't be afraid. Usually, things work very well. In 5 years, it has only happened once that a developer had his work put kept in KDE while he wanted to remove it.

Go to KDE Identity, fill out the form and describe why you need write access. Make sure to specify your full name and e-mail address.

Please also include the name of your bugs.kde.org account, if non-existent please create one so that it can be given usual developer rights. Closing bugs.kde.org reports with keywords in commit comments only works if the email address of your KDE Identity and bugs.kde.org accounts match. You can change your bugs.kde.org address in the Bugzilla user settings.

Git requires use of an ssh key, and new accounts for SVN must also choose the svn+ssh protocol. Send a public ssh key (e.g. ~/.ssh/id_dsa.pub)

If you are contributing to an application that is not yours, it is a good idea to first submitting your coding as patches to the author and let him apply them. If the author is not maintaining his application, you might become the new maintainer...

Although there are few restrictions on repository commit rights, we expect you not to disrupt other developers' code without their consent. You must also respect the feature freezes of the release schedule (published on Schedules page)

A detailed list of rules you should follow when committing to KDE repositories are listed in the KDE Commit Policy.

As a first step, we can put it in playground, which is essentially "kde-alpha". Develop it there and when it is ready, request that your app to be moved to the appropriate KDE package or the extragear module.

It contains Qt bindings for Ruby, PHP, C# to use Qt classes with those langages, KDE bindings for Ruby, C#, python to use KDE classes with those langages, and XParts to embed non-KDE apps as a KPart. Check the binding page of TechBase.

No, playground are not a released packages. The same is true for kdereview and extragear: they are not frozen and released. But if you want your app to move to a package, ask for it before the beta-release.

[edit]Qt-copy or Qt from qt.digia.com: if one were doing a clean build of trunk, which would be preferable?

You can use either. They are binary compatible (forward and backward). There can be, however, a few bugfixes in qt-copy over the most recent Qt release. Especially if building from qt-copy, pay attention to the apply-patches script.

[edit] How can I get one of the KDE application as a standalone tarball?

If you reported a bug that is fixed in a new release of KDE but is still reported as open, you can close it. It might happen because your bug is the same as another one, or simply because the developer fixed something without noticing that it would correct your bug.

You can do that from your Subversion commit. To do so, append to your commit message a line like this:

BUG: XXXXX where XXXXX is the bug report you want to close. If the report you're closing is adding a new feature, you can use FEATURE instead of BUG.

Managing a bug list is a huge task for the developers and they usually have a lot of bugs listed, some being fixed already without their knowledge, some being unreproducible, some without enough information to be corrected, etc. If you can help by managing and updating the list of outstanding bugs, you will be gladly welcome. And you will receive an even happier welcome if you provide a patch.

SSH makes use of two keys: a private key and a public key. You should keep the private key secret at all times and only place it on machines over which you have direct control. Public, shared, and community machines are not suitable environments to store SSH private keys. Take action to help prevent theft of your SSH private key data. Setting a password on your SSH private key will help reduce the risks involved with private key theft.

Generate a key pair for each major location you work from. This helps to reduce the impact when your key gets stolen.
When someone obtains access to your private key, your key can be abused in attempts to compromise KDE servers. Well known open source projects have been compromised this way in the past, YOU must help us to make sure that this doesn't happen with KDE servers as well. For that reason it is important to notify sysadmin (at) kde (dot) org immediately when you notice that someone may have had access to your private key for example when a computer on which it was stored has been hacked or infected with a virus, worm or trojan.

If you choose to make a backup of your SSH private key data, please ensure that any such backup is stored in a secure manner as well.

For the practical part, the following command can be used to generate a SSH private/public key pair with
ssh-keygen -t dsa
This will create a private key as ~/.ssh/id_dsa and a public key as ~/.ssh/id_dsa.pub.

There are times when you may want to use a key of a different name to the default, perhaps to use separate keys for different projects. To let SSH know which key you want to use for KDE.org, you can keep a list of servers and their corresponding keys in ~/.ssh/config. For example,

Host svn.kde.org
IdentityFile ~/.ssh/id_dsa_kde

In order to use SSH to access KDE servers you need to send your public key to sysadmin (at) kde (dot) org.

The kde-commits mailinglist carries automatic notifications for all changes made in the KDE repositories. The KDE-Commits mailinglist is very high traffic. An alternative is CommitFilter which allows you to get notification for only those areas that interest you.